Supabase won't redirect to MAUI Blazor App

[Dayjay]

Hey,

I am using Supabase and WinUIEx for the authentication in my MAUI Blazor Hybrid App. This is the code I am using:

var state = await Supabase.Auth.SignIn(Constants.Provider.Azure, new SignInOptions
    {
        FlowType = Constants.OAuthFlowType.PKCE,
        RedirectTo = "myclient://oauth/callback"
    });

var result = await WinUIEx.WebAuthenticator.AuthenticateAsync(state.Uri, new Uri("myclient://oauth/callback"));

//do stuff with the result - but I never get here

When I call the code it opens the browser window (tried with Firefox and Edge) but I end up with the following error:

I tried pasting the state.Uri in the browser and it works, it even opens my maui app (again since its already open).
I also added the url as a valid redirect url in the Supabase dashboard.

Is there something I am missing?

[dotMorten]

I end up with the following error:

Where is this error happening? What URL is the browser trying to open? How is that different from state.Uri ?

Wrt Firefox, see #117

[Dayjay]

Hey,

This is the URL (=state.Uri) it opens in the browser and that I just pasted:

https://1234567890.supabase.co/auth/v1/authorize?flow_type=pkce&code_challenge=dskhflsdkgaljfflashfkjsgladas&code_challenge_method=s256&provider=azure&redirect_to=myclient%3a%2f%2foauth%2fcallback

The error I posted is the response I get in the browser from the supabase API. Doesn't matter which browser.
The error only appears if I use the WinUIEx.WebAuthenticator.

Even if I use NavigationManager.NavigateTo() it opens the Browser window fine and opens the app again.

Just to clarify the workflow:

• Login Button gets clicked
• Calls the Supabase URL I posted above
• Supabase redirects to my provider (in my case Azure)
• Azure redirects back to Supabase
• Supabase should redirect back to my app (this is when I get the error)

Honestly wouldn't be surprised if this is just another annoying MAUI Bug somehow.

[dotMorten]

Sorry I don't have much more to go on. It might be worth cloning this repo, and change the oauth sample page to use your service, and just step through winuiex and see if you can spot what's going wrong, compared to how for instance Maui's WebAuthenticator is behaving.

[Dayjay]

Will do and report back later.

But thank you very much. 👍

[Dayjay]

Thinking about it, I bet it breaks because the WebAuthenticator runs inside the BlazorWebView MAUI Hybrid creates and not the actual Maui Thread.

Would also explain why the instance id is emtpy and why other stuff maybe fails.

[dotMorten]

No idea. I’ve never used Maui blazor. But try the sample app to confirm if it works outside blazor

[Dayjay]

Tried different things over the weekend with Hybrid MAUI but no success.

In the Platforms/Windows/App.xaml, if I understood it correct, it should at least set a guid as key but not even that is happening:

activatedEventArgs is not null. However, the Kind is ExtendedActivationKind.Launch and not ExtendedActivationKind.Protocol.

Edit: Forget what I said, I think I misunderstood what the function does.

[Dayjay]

I got it working. :)

I copied your WebAuthenticator to my project and adjusted it so it would work with the Supabase API.

Mainly:

I don't pass the state parameter anymore - supabase just doesn't like it. It's a bit problematic because I don't know the Id of the task anymore in the callback but for my use case it shouldn't be a problem (I think).

The appInstanceId can always be the same and in the ResumeSignin I just get the first task and remove it before I set the result.